In the very popular games of baseball and softball, bases are used to mark three of the four corners of the baseball diamond around which the batter must run after hitting the ball. These are known as first, second and third base. Conventionally, the bases are made from canvas material with foam or other soft filling. Typically, the bases are held in position by steel pegs which are driven into the ground and then strapped to the bases.
Unfortunately, the game is such that a runner will often attempt to slide into the base in order to avoid being tagged by the baseman. Often, what happens is that the sliding player comes into contact with the steel peg, resulting in injury. These injuries occur at every level of play and in every age group, particularly with the increasing popularity of slow-pitch baseball.
The types of injuries that occur range from mere bruises to cuts, torn ligaments or muscles, and more commonly to compound fractures of the legs, ankles and feet. These types of injuries often have crippling effects on the victim which last the rest of his life.
One attempt to remedy this kind of problem is exemplified in U.S. Pat. No. 3,862,756, issued Jan. 28, 1975 to C.J. Selliken. The Selliken device incorporates a first member with a top plate and means for anchoring the top plate in base position with the upper surface of the top plate substantially flush with the ground, along with a second member resembling a baseball base, the second member having a bottom surface arranged to overlie the upper surface of the first member in its installed base position. Selliken then provides magnetic holding means in the upper surface of the first member and the bottom surface of the second member, the magnetic means holding the members together but allowing them to separate under unusual force conditions. More specifically, Selliken provides four individual magnets at the four corners of the base, these being adapted to interact with ferromagnetic means.
What is lacking in Selliken is any means by which to vary the force with which the base is held in place. It will be appreciated that the "separation force" required for big league hardball is quite different from that required in a children's softball game.